It has been demonstrated that the hydrodynamic process known as supercavitation reduces overall drag (viscous and pressure) by a factor of 26 (Minehart, 2003). Independent of the approach to produce the supercavitation envelope, the stability of the envelope is susceptible to external shocks and abrupt turns, (Minehart, 2004). The instability of a supercavitating envelope was demonstrated when envelope closure (collapse) was achieved by the exertion of an external pressure wave with a magnitude of sixteen times (16) the on-coming dynamic pressure (½ρV2). Although it was demonstrated that the adaptation of micro-foils to a rocket torpedo would stabilize its flight and reduced adverse yawing affects (due to envelop closure) by a factor of five (5), the associated envelop closure induced a highly transient drag condition that made the torpedo unnecessarily susceptible to hostile counter-measures (Minehart, 2004).
It was demonstrated in 2005 that a porous plate torpedo skin would not only prevent envelop closure in the presence of external pressure waves, this unique approach eliminated all adverse yaw affects during extreme maneuvers (turns). The use of a porous plate gas ejection also proved, for the first time, a capability for a supercavitation torpedo to operate at substantially greater depths.
It is important to note that this invention is independent of whatever means is used to produce the supercavitating envelope, e.g., direct gas injection, an external cavitator, or a hybrid approach. The denominator of the associated ejection ratio is based on the initial tip gas volume that is independent of it means of production.